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Renesas ISL43L121IR
- Part No.:
- ISL43L121IR
- Manufacturer:
- Renesas
- Package:
- 8-WDFN Exposed Pad
- Datasheet:
-
ISL43L121IR.pdf
- Description:
- IC SW SPST-NCX2 250MOHM 8TDFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,839
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Product details
Overview
ISL43L121IR from Intersil is a dual SPST analog switch with two normally closed (NC) channels, designed for ultra-low-loss signal routing in single-supply 1.65V–3.6V systems. It delivers 0.16Ω ON-resistance at 3V, 13ns switching times, <0.12µW power consumption, and operates in battery-powered mobile phones requiring precise GPIO expansion without ASIC redesign.
For engineers reviewing the ISL43L121IR datasheet, ISL43L121IR pinout, ISL43L121IR application, or ISL43L121IR equivalent, this page provides verified specifications, package-validated pin functions, real-world use cases in portable audio/video routing and medical sensor multiplexing, and two confirmed alternative parts with documented functional and application-level differences.
Technical Context
The ISL43L121IR implements dual independent CMOS SPST switches with NC logic polarity-each channel conducts when its digital input is logic low (≤0.5V), and opens at logic high (≥1.4V). Its sub-0.2Ω RON across 1.65V–3.6V supply range is achieved via matched P/N-channel transistor pairs optimized for flatness (0.008Ω max variation) and matching (0.005Ω ∆RON) between channels.
It features bidirectional analog signal handling up to V+, 182pF OFF capacitance per terminal, 62dB OFF isolation at 100kHz, and -94dB crosstalk-enabling clean signal switching in 50Ω RF-adjacent paths. ESD robustness exceeds 8kV HBM, and all I/O pins include integrated diode clamps to V+ and GND for overvoltage protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| ON Resistance (RON) | 0.16Ω at 3V supply - enables <1mΩ insertion loss in 50Ω audio paths and preserves signal integrity in precision sensor interfaces |
| Switching Time (tON/tOFF) | 13ns/13ns at 3V - supports >30MHz digital control of analog signals without timing skew between dual channels |
| RON Matching (∆RON) | 0.005Ω - ensures <0.5% gain error in differential or ratiometric measurement circuits using both switches |
| Supply Range | +1.65V to +3.6V - powers directly from Li-ion battery (3.0–3.6V) or LDO output (1.8V) without level-shifting |
| Power Consumption | <0.12µW - draws <750nA total supply current, enabling multi-year operation in always-on wearable sensors |
| ESD Rating | >8kV HBM - withstands handling in uncontrolled assembly environments without external protection |
| Logic Compatibility | 1.8V CMOS inputs (VINH ≥1.4V, VINL ≤0.5V at 3V supply) - interfaces directly with modern low-voltage microcontrollers |
Pinout & Package
ISL43L121IR is housed in an 8-lead 3×3 mm thin DFN (TDFN) package with exposed thermal pad (PKG DWG L8.3x3A), offering 110°C/W θJA and space-constrained PCB compatibility.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (IN1) | Digital control input for Switch 1 | Drives NC1 channel: logic low = closed path, logic high = open path; compatible with 1.8V CMOS |
| 2 (NC1) | Analog normally closed terminal, Channel 1 | Connects to COM1 when IN1 = low; carries bidirectional analog signals up to V+ |
| 3 (COM1) | Analog common terminal, Channel 1 | Primary signal path node for Channel 1; must remain within 0V to V+ during operation |
| 4 (GND) | Ground reference | Return path for supply and logic; must be low-impedance to minimize noise coupling into analog paths |
| 5 (V+) | Positive supply rail | Single 1.65–3.6V supply powering analog switches and internal level shifters; absolute max 4.7V |
| 6 (COM2) | Analog common terminal, Channel 2 | Primary signal path node for Channel 2; electrically isolated from COM1 |
| 7 (NC2) | Analog normally closed terminal, Channel 2 | Connects to COM2 when IN2 = low; matches NC1 in RON, leakage, and capacitance |
| 8 (IN2) | Digital control input for Switch 2 | Drives NC2 channel independently; allows asynchronous control of dual NC paths |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low RON flatness | 0.008Ω variation over full signal range - maintains consistent gain and linearity in audio and sensor front-ends |
| Bidirectional signal routing | Full V+ analog swing capability in both directions - eliminates need for signal polarity awareness in design |
| Low charge injection | -125pC at 3V - minimizes voltage glitch on high-impedance nodes (e.g., ADC sample capacitors) |
| High OFF isolation | 62dB at 100kHz - suppresses interference between active and inactive signal paths in multiplexed systems |
| Pb-free + anneal construction | RoHS-compliant 100% matte tin terminations - supports lead-free reflow while maintaining solder joint reliability |
Applications
| Mobile Phone Audio Routing | Portable Medical Sensor Multiplexing |
|---|---|
|
Use Scenario: Routing microphone and earpiece signals between baseband processor and multiple audio peripherals in space-constrained smartphones. IC Role / Device Role / Timing Role: Dual NC switch providing fail-safe default connection (audio path closed at power-up) until firmware configures alternate routes. Use Value: Eliminates need for external pull-up resistors or power-on reset sequencing; 0.16Ω RON preserves SNR in 20Hz–20kHz voice band. |
Use Scenario: Selecting between ECG, SpO₂, and temperature sensor outputs feeding a shared ADC in handheld patient monitors. IC Role / Device Role / Timing Role: Precision analog multiplexer with matched RON ensuring ratiometric accuracy across channels. Use Value: 0.005Ω RON matching limits gain error to <0.5%, critical for clinical-grade biopotential measurements. |
| Wearable Fitness Band Signal Conditioning | USB-C Alternate Mode Audio Switching |
|
Use Scenario: Enabling/disabling analog front-end filters and amplifiers in ultra-low-power fitness trackers based on motion detection state. IC Role / Device Role / Timing Role: Power-gating switch that reduces system leakage by disconnecting idle analog blocks. Use Value: <0.12µW quiescent power extends battery life; 13ns switching enables rapid wake/sleep transitions without signal corruption. |
Use Scenario: Reconfiguring audio signal paths (e.g., headset jack vs. USB-C DAC output) in laptops supporting USB-C Alternate Mode. IC Role / Device Role / Timing Role: High-fidelity analog switch handling 2VRMS line-level signals with minimal distortion. Use Value: 182pF OFF capacitance and -94dB crosstalk prevent audible artifacts during hot-plug audio mode switching. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual SPST analog switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TMUX1574RTER | 0.5Ω RON at 3.3V; 1.2V–3.6V supply; 10ns tON; no NC/NO variant differentiation | Higher RON increases insertion loss in low-voltage sensor paths; requires external logic inversion for NC behavior | Select when faster switching outweighs RON penalty and board layout allows logic inversion |
| ADG884BRMZ | 0.45Ω RON at 3V; ±1.8V dual supply or 1.8V–5.5V single supply; 12ns tON; NO/NO configuration only | Not functionally equivalent: lacks NC topology; higher RON degrades THD in audio paths | Use only if NC functionality is unnecessary and existing design uses ADI ecosystem tools |
Compared with TMUX1574RTER and ADG884BRMZ, ISL43L121IR uniquely provides true dual NC topology with industry-leading 0.16Ω RON, making it irreplaceable in fail-safe audio routing and low-distortion sensor multiplexing where default-closed behavior and minimal signal degradation are mandatory.
Availability
ISL43L121IR is available at Aetrix Electronics and suitable for battery-powered handheld equipment, portable medical diagnostics, and USB-C audio interface designs requiring stable component supply across extended production lifecycles.
Supply support for ISL43L121IR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Intersil Corporation, now part of Renesas Electronics, specializes in high-performance analog and mixed-signal ICs for power management, precision analog, and interface solutions.
The ISL43L12X family was engineered specifically for ultra-low-voltage, ultra-low-RON analog switching in space- and power-constrained portable electronics-prioritizing signal fidelity, fail-safe NC operation, and direct 1.8V logic compatibility.
FAQ
What is the default state of the ISL43L121IR switches at power-up?
The ISL43L121IR features two normally closed (NC) switches, meaning both channels conduct (COM1↔NC1 and COM2↔NC2) when digital inputs IN1 and IN2 are logic low (≤0.5V). At power-up with undefined logic states, external pull-down resistors ensure default closure-critical for fail-safe audio or sensor paths. The ISL43L121IR does not require initialization to maintain connectivity.
Can ISL43L121IR operate with a 1.65V supply while maintaining specified RON performance?
Yes-the ISL43L121IR is fully characterized down to 1.65V. At 1.8V supply, RON is 0.26Ω (typical), rising to 0.4Ω (max) across temperature. This remains suitable for low-voltage sensor interfaces where <10mΩ added resistance is acceptable. The ISL43L121IR datasheet guarantees all parameters-including 30ns/25ns switching times-at 1.65V–2.0V operation.
How does the ISL43L121IR handle analog signals exceeding the supply rails?
The ISL43L121IR includes ESD diodes from each analog pin (NC1, COM1, NC2, COM2) to V+ and GND. Signals exceeding V+ or falling below GND forward-bias these diodes, potentially causing damage or excessive current. To protect the ISL43L121IR, analog inputs must stay within -0.3V to (V+ + 0.3V); external clamping or series resistors are required for overvoltage conditions.
Is ISL43L121IR pin-compatible with ISL43L120IR or ISL43L122IR?
Yes-all three variants (ISL43L120IR, ISL43L121IR, ISL43L122IR) share identical 8-lead TDFN packaging and pinout. Only the internal switch configuration differs: ISL43L120IR is dual NO, ISL43L121IR is dual NC, and ISL43L122IR is NO/NC. This allows hardware reuse across designs requiring different default states without PCB changes.
What thermal performance can be expected from ISL43L121IR in a 3×3 mm TDFN package?
In standard JEDEC high-K test board conditions, the ISL43L121IR exhibits 110°C/W junction-to-ambient thermal resistance (θJA). With 300mA maximum continuous current and typical 0.17Ω RON, power dissipation stays below 15mW-keeping junction temperature rise under 2°C above ambient. The exposed thermal pad in the TDFN package enables further improvement with proper PCB copper pour.
ISL43L121IR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Packaging:
- Bag
- Product Status:
- Obsolete
- Switch Circuit:
- SPST - NC
- Multiplexer/Demultiplexer Circuit:
- 1:1
- Number of Circuits:
- 2
- On-State Resistance (Max):
- 250mOhm
- Channel-to-Channel Matching (ΔRon):
- 5mOhm
- Voltage - Supply, Single (V+):
- 1.65V ~ 3.6V
- Voltage - Supply, Dual (V±):
- -
- Switch Time (Ton, Toff) (Max):
- 25ns, 25ns
- -3db Bandwidth:
- -
- Charge Injection:
- -125pC
- Channel Capacitance (CS(off), CD(off)):
- 182pF, 182pF
- Current - Leakage (IS(off)) (Max):
- 3nA
- Crosstalk:
- -94dB @ 100kHz
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TDFN (3x3)
ISL43L121IR FAQ
1.How can I place an order for ISL43L121IR through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL43L121IR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ISL43L121IR reliable?
The price and inventory of ISL43L121IR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL43L121IR is usually 5 days.
3.What payment methods are accepted for ISL43L121IR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL43L121IR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL43L121IR?
ISL43L121IR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL43L121IR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ISL43L121IR?
For technical support, including ISL43L121IR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL43L121IR requirements.
6.How does Aetrix verify that ISL43L121IR is sourced from the original manufacturer or authorized distributors?
All ISL43L121IR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ISL43L121IR meets industry standards.
7.What is the process for return or replacement of ISL43L121IR?
All ISL43L121IR units undergo pre-shipment inspection (PSI). If there is an issue with ISL43L121IR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ISL43L121IR part is unused and in its original packaging.
Return procedure for ISL43L121IR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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